Clothes dryer with starter safety switch

ABSTRACT

A clothes dryer includes a rotatable drum having an access door and a starting switch adapted to be closed when the door is closed and a manual push bottom is actuated, so that even when a little child enters the drum and closes the door the dryer is not started. The improvement resides in a simple mechanism without any complicated electrical parts such as a relay for ensuring the safety of operation.

United States Patent 1191 Takeyama 11 3 ,803,725 14 1 Apr. 16, 1974 CLOTHES DRYER WITH STARTER SAFETY SWITCH [75] Inventor:

[73] Assignee: Matsushita Electric Industrial Co.

Ltd., Osaka, Japan 22 Filed: Sept. 8, 1972 21 Appl. No.: 287,472

Kojiro Takeyama, Kawanishi, Japan [30] Foreign Application Priority Data 0m. 29, 1971 Japan.. 46-86465 [52] US. Cl. 34/133, ZOO/61.62 [51] Int. Cl..F26b 11/02, HOlh 15/14, l-lOlh 13/18 [58] Field of Search 200/6162, 61.64, 61.67, 1 200/6170, 61.76, 61.7861.81

[56] References Cited UNITED STATES PATENTS 3,713,226 1/1973 Takeyama 34/53 3,609,265 9/1971 Garbe et al. ZOO/61.62 3,546,410 12/1970 Brighenti ZOO/61.62 3,273,256 9/1966 Behrens.....

2,769,246 12/1956 Shapter 34/133 Primary ExaminerWilliam F ODea Assistant ExaminerPaul Devinsky Attorney, Agent, or Firm-Stevens, Davis, Miller &

Mosher [5 7 ABSTRACT 2 Claims, 6 Drawing Figures sgwmafi PATENTED APR 1 8 I974 SHEET 1 HF &

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, CLOTHES DRYER WITH 'STARTERISAFETY SWITCH BACKGROUND OF THE INVENTION The present invention relates to a rotatable drum type clothes dryer and, more particularly, to safety means therefor.

Conventionally, this type of dryer usually has safety means such as a door switch so that it cannot start to operate as long as an access door is not closed.

l-Iowever,'a door switch is not sufficient to provide a satisfactory safety guard. For example, when a little child enters. the drum of the dryer and closes the access door from inside, there may occur an adverse accident. Thus, there is a need for a clothes dryer which does not start to operate even when a time switch is pre-set and the access door is closed, unless a start switch is actuated.

SUMMARY OF THE INVENTION Thepresent invention has been achieved in view of the above 'andhas asa'n object to provide a clothes dryer including a microswitch which can be closed only when grooves in a pair of slidable members align with each other so that, even when a time switch is preset and an access door isclosed, the dryer cannot start to operate. t

A further object of the present invention is to provide a clothes dryer which is simple in construction and less expensive to manufacture byproviding a'microswitch which serves as a door switch and at the same time as a start switch. I v

A still furtherobject of the present invention is. to provide a clothes dryer in which, even when grooves in a pair of slidable members align with each other to close a microswitch and the dryer is being operated, the microswitch can be opened as soon as the access door is opened toensure a safe operation.

A further object of the present invention is to provide a clothes dryer which has a start switch provided on the upper part of dryer housing so as to facilitate its handling. I

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view of a clothes dryer embodying the present invention with a part broken away'in order to show the interior of the dryer; i

' FIG. 2 is a vertical sectional view of the dryer shown in FIG. 1; I

FIG. 3 is a fragmentary enlarged sectional view;

FIG. 4 is a sectional view showingaswitch actuating mechanism, the switch being shown in the opened position; I

FIG 5 is a view similar to FIG. 4 but showing the switch in closed position; and I F166 is an electrical circuit diagram used in the clothes dryer.

DESCRIPTION OF A PREFERRED EMBODIMENT An embodiment of the present invention will now be described with reference to the accompanying drawings in which reference numeral (1) designates an outer housing 'of a dryer. Reference numeral (2) indi- 'cates a rotatable drum supported in said outer housing (1) with an axis of rotation extending horizontally. Reference numeral (3) represents a condenser type motor for driving the rotatable drum (2) and an exhaust blower (4). The motor (3) is mounted on the bottom of the outer housing (1) by means of a bracket (3). Reference numeral (5) designates an opening provided in the front face of the rotatable drum (2) for throwing clothes into the dryer. Reference numeral (6) indicates an access door mounted on said outer housing (1) and adapted to close said opening (5), numeral (7) indicating a plurality of perforations formed in the front face of the rotatable drum (2), and numeral (8) indicating a heater mounting plate disposed in such a'manner that it covers the front face portion of the rotatable drum (2). The heater mounting plate 8) has a lower portion extending downwardly beyond the outer periphery of the drum (2) to provide an extension (8') on which an electrical heater (9) is mounted. Reference numeral (10) designates an insulator provided. on the heater mounting plate (8) for supporting the heater (9), reference numeral (11) indicating a flange formed on the inner peripheral portion of the plate (8) for rotatably supporting the front part of the drum (2) througha low friction seat (12) made of Teflon (Trade Mark) or the like material. Reference numeral (13) designates a fine mesh screen filter made of nylon or the like material and provided at the center part of therear portion of the drum (2), referencenumeral (14) indicating a filter cover made of polypropylene or the like material and fitted at its outer periphery to projections;(2') of the drum (2). As shown in FIG. 2, the filter cover (14) holds the filter (13) at its inner periphery and is resiliently fitted at its outer periphery to the projections (2) on the drum (2). Thus, the cover (14) can readily be removed and replaced in position. Reference numeral (15) designates a plane belt extending around a' driving pulley (16) and the drum (2) for driving the latter. Reference numeral 17) designates an idler pulley for tensioning the belt (15), reference numeral (18) indicating a driving belt for the blower (4) extending around a blower driving pulley (19) on the motor (3) and a pulley( 21) provided on a blower shaft (20).--Numeral (22) designates a blower casingwhich rotatably supports a drum shaft ('24) at its central portion through a self-centering bearing (23), so'as to rotatably support therear portion of the rotatable drum (2). Numeral (25) designates a plurality of baffle plates made of a plastic material such as polypropylene and disposed, in the rotatable drum (2) for causing the clothes to be dried to'revolutionally fall inthe drum and for agitating the clothes; Reference'numeral (26) designates -a belt cover mounted at the lower portion of the rear (3). Numeral (28) designates caster wheels provided at v the outside of-the bottom of the outer housing (1 numeral (29) indicating a plurality of perforations formed in the rear face of the drum (2), numeral (30) indicating air exhaust holes formed in the blowercasing (22), numeral (31) representing a plurality of partition plates provided on the baffle plate (25), numeral (32) indicating an air exhaust hole provided at the upper-portion of the rear face of the housing (1), and numeral (33) indicating a time switch mounted at the front upper portion of the housing (1) for time controlling the motor circuit and the heater circuit as shown in FIG. 6.

Reference numeral (34) designates a start switch mounted on the housing (1) at a position above the time switch (33). The construction of the start switch (34) will be described with reference to FIGS. 2 through 4. In the drawings, reference numeral (35) designates a door packing for air-tightly sealing the opening when the door (6) is closed, numeral (36) indicating a lever mounted on the front face of the housing 1) by a pin (37) and having a projection (36) at one end. The projection (36) is moved in the direction shown by an arrow A (in FIG. 3) when the door (6) is closed. Further, the other end (36") of the lever (36) is in abutting relation with a sliding plate (38) of the start switch (34). The reference numeral (39) designates a manual push button mounted on the front face of the outer housing (1). When the push button (39) is depressed, another sliding plate (40) of the start switch (34) is pushed in the direction shown by the arrow B. Numeral (41) designates screws for mounting the sliding plate (40) on the cylindrical portion (39') of the push button (39), numeral (42) indicating a substantially U-shaped mounting plate for slidably holding the cylindrical portion (39) of the push button (39). The mounting plate (42) is secured at its opposite ends to the outer housing (1). Reference numerals (43) and (44) designate a flat mounting plate and a substantially U-shaped mounting plate, respectively, for slidably holding the sliding plates (38) and (40), respectively, numeral (45) denoting a spring disposed around the cylindrical portion (39) of the manual push button for applying a returning force to the push button (39). Numeral (46) designates a spring having one end secured to the U-shaped mounting plate (44) and the other end to one end (38') of the L-shaped sliding plate (38) for urging the sliding plate (38) into abutting engagement with the end (36") of the lever (36). Numeral (47) shows a U-shaped slanted cut-out groove formed in the substantially central portion of the sliding plate (38). The groove (47) has an edge (47) which is slightly inclined with respect to a path along which the plate (38) is slidably moved by the lever (36). The sliding plate (40) also has at its center portion a U-shaped groove (48). There is disposed a microswitch (49) which has an actuating pin (50) adapted to be inserted into the grooves (47) and (48) when they are aligned with each other. The pin (50) of the microswitch (49) is so biased that it projects outwardly and the microswitch is so constructed that it is closed when the pin (50) engages with the grooves (47) and (48). The sliding plates (38) and (40) are so disposed that they can be superposed one on the other.

Referring now to the electrical circuit shown in FIG. 6, the switch (34) is positioned between a suitable power source (51) and the time switch (33) in a series relation with the latter. Reference numeral (52) designates a capacitor for the motor (3), numeral (53) representing a timing motor for driving the time switch (33), numeral (54) representing a thermostat, andnumeral (55) representing a heater.

In operation of the above arrangement, clothes are thrown into the rotatable drum (2) and then the timeswitch (33) is actuated and the access door (6) is closed. When the door (6) is closed, the projection (36) of the lever (36) is pushed in the direction shown by the arrow (A) and the end (36") of the lever (36) is moved about the pin (37) in the direction shown by the arrow (C) in FIG. 5 so as to displace the sliding plate (38) from the position shown by dotted lines to the position shown by solid lines. This movement causes the groove (47) in the sliding plate (38) to move to a position directly beneath the pin (50) of the microswitch (49). In this position, since a portion of the pin (50) is on the upper surface of the sliding plate (40), the microswitch (49) is not closed, so that the apparatus does not start to operate.

When the manual push button (39) is depressed in the direction of the arrow (d) in FIG. 5 against the action of the spring (45 the sliding plate (40) having the groove (48) is caused to move in the direction shown by the arrow B in FIG. 4. Thus, the groove (48) is placed directly beneath the pin (50) of the microswitch (49). Therefore, the pin (50) of the microswitch (49) is allowed to be inserted into the grooves (47) and (48) and the microswitch (49) is closed to start the machine.

The atmospheric air is introduced through the air intake hole (27) formed in the rear portion of the housing (1) and passed about the motor (3) toward the mounting plate (8) effectively cooling the motor (3). The air is then passed through the space between the mounting plate (8) and the rotatable drum (2),-heated by the heater (9) and thereafter introduced through the perforations (7) into the drum (2). The hot air in the drum (2) is circulated by the baffle plate (25) and distributed in the drum (2). The hot air which has passed through the drum (2) is directed to flow through the cover (14) and the filter (13) and filtered there-by. Thus, only wet air is exhausted from the housing (1) through hole (32).

When the operation is terminated, the door (6) is opened. Thus, the pressure on the lever (36) is released. Therefore, the end (36) of the lever (36) is returned in the direction shown by the arrow (e) in FIG. 5 under the action of the apring (46). In this instance, since the slanted edge (47') of the groove (47) pushes the pin (50) of the switch (49) upwardly, the pin 50 is disengaged from the groove (48). Thus, the manual push button (39) is returned to its original position together with the sliding plate (40). When the pin (50) is pushed upwardly, the switch (49) is opened.

The present invention has thus been shown and described with reference to a preferred embodiment, however, it should be noted that the invention is not limited to the detail of the illustrated structure but many changes and modifications can be made without departing the scope of the appended claims.

What is claimed is:

1. In a clothes dryer comprising an outer housing, a drum rotatably supported in said housing with an axis of rotation thereof extending substantially horizontally, a motor for driving said drum, said drum having an opening in the front side thereof for loading and unloading clothes into and out of said drum, a door mounted on said housing adjacent said opening for pivotal movement between open and closed positions, and a switch for starting the operation of said dryer, the improvement comprising a mechanism for operating said switch, said mechanism including:

a. a lever member pivotally mounted on said outer housing at a first portion between ends of said lever member, said lever member having a second portion adjacent one of said ends, said second portion being positioned in a path of the pivotal movement of said door so that said lever member is pivotally c. a first elongated member extending within said housing in substantially parallel relationship to said push button and having an end secured to said push button for substantially linear movement thereby,

d. a first biasing means normally urging said push button in one of its axial directions,

e. a second elongated member adjacent said first elongated member and mounted for substantially linear movement with respect to said first elongated member into and out of a position in which said first and second elongated members are superposed one on the other,

f. said lever member having a third portion adjacent the other end thereof in abutting relationship to an end of said second elongated member whereby, upon pivotal movement of said lever member, said second elongated member is moved into said superposed position with respect to said first elongated member,

g. said switch having an actuating pin extending therefrom and resiliently urged against a longitudinal surface of each of said first and second elongated members, and

h. said first and second elongated members being formed with grooves in the surfaces thereof against which said actuating pin of said switch is urged, the arrangement being such that said grooves are aligned with each other to allow said actuating pin to be moved into the aligned grooves only when said door is moved to its closed position and said push button is pushed.

2. A switch operation mechanism according to claim 1 further including a second biasing means urging said second elongated member against said lever member, and the groove in said second elongated member having an edge inclined with respect to the surface of said second elongated member in contact with said actuating pin. 

1. In a clothes dryer comprising an outer housing, a drum rotatably supported in said housing with an axis of rotation thereof extending substantially horizontally, a motor for driving said drum, said drum having an opening in the front side thereof for loading and unloading clothes into and out of said drum, a door mounted on said housing adjacent said opening for pivotal movement between open and closed positions, and a switch for starting the operation of said dryer, the improvement comprising a mechanism for operating said switch, said mechanism including: a. a lever member pivotally mounted on said outer housing at a first portion between ends of said lever member, said lever member having a second portion adjacent one of said ends, said second portion being positioned in a path of the pivotal movement of said door so that said lever member is pivotally moved by said door when the latter is moved to its closed position, b. a manual push button having a portion slidably extending throughout the wall of said outer housing, c. a first elongated member extending within said housing in substantially parallel relationship to said push button and having an end secured to said push button for substantially linear movement thereby, d. a first biasing means normally urging said push button in one of its axial directions, e. a second elongated member adjacent said first elongated member and mounted for substantially linear movement with respect to said first elongated member into and out of a position in which said first and second elongated members are superposed one on the other, f. said lever member having a third portion adjacent the other end thereof in abutting relationship to an end of said second elongated member whereby, upon pivotal movement of said lever member, said second elongated member is moved into said superposed position with respect to said first elongated member, g. said switch having an actuating pin extending therefrom and resiliently urged against a longitudinal surface of each of said first and second elongated members, and h. said first and second elongated members being formed with grooves in the surfaces thereof against which said actuating pin of said switch is urged, the arrangement being such that said grooves are aligned with each other to allow said actuating pin to be moved into the aligned grooves only when said door is moved to its closed position anD said push button is pushed.
 2. A switch operation mechanism according to claim 1 further including a second biasing means urging said second elongated member against said lever member, and the groove in said second elongated member having an edge inclined with respect to the surface of said second elongated member in contact with said actuating pin. 